Network+ N10-006 Chapter 2

What are two types of Synchronizing?

1. Asynchronous 2. Synchronous

What are the characteristics of Logical Link Control (LLC)

1. Connection Services 2. Synchronizing transmissions

What is the Network Layer responsible for?

1. Logical addressing 2. Switching 3. Route discovery and selection 4. Connection Services 5. Bandwidth usage 6. Multiplexing strategy

What are the characteristics of MEDIA ACCESS CONTROL (MAC)

1. Physical addressing 2. Logical topology 3. Method of transmitting on the media

What are some of the common approaches to Multiplexing strategy

1. Time division multiplexing (TDM) 2. Statistical time division multiplexing (StatTDM) 3. Frequency division multiplexing (FDM)

What is the well known UDP port number for NTP?

123

What is USER DATAGRAM PROTOCOL (UDP)

A connectionless transport protocol that provides unreliable transport, in that if a segment is dropped, the sender is unaware of the drop, and no retransmission occurs

At the Layer 4 Transport Layer, what is BUFFERING?

A device allocates a chunk of memory (called a buffer or queue) to store segments if bandwidth is not currently available to transmit those segments.

What is TRANSMISSION CONTROL PROTOCOL (TCP)

Connection-oriented transport protocol provide reliable transport, in that if a segment is dropped, the sender can detect that drop and retransmit that dropped segment.

At the Network Layer, what is Flow Control?

Helps prevent a sender from sending data more rapidly than the receiver is capable of receiving.

What is Baseband?

Uses all the available frequencies on a medium to transmit data.

What is Synchronizing Bits?

When two network devices agree when one bit stops and another bit starts.

What are the two common Flow Control approaches at Layer 4 Transport Layer?

Windowing Buffering

What is Packet Switching?

With packet switching, data stream is divided into packets. Each packet has a Layer 3 header, which included a source and destination Layer 3 address.

4. Transport layer

Acts as the dividing line between the upper layers and lower layers of the OSI Model. Messages taken from the upper layers (Layers 5-7) are encapsulated into segments for transmission to lower layers (Layers 1-3) Date streams coming from lower layers are decapsulated and sent to Layer 5 the Session Layer. Two Protocols in the the Transport Layer. UDP TCP

What is Multiplexing strategy?

Allows multiple communications sessions to share the same physical medium

At the Network Layer, what is Packet reordering?

Allows packets to be placed in the appropriate sequence as they are sent to the receiver.

What are the Layers of the TCP/IP Stack?

Application (layers 7-5 of OSI) Transport (Layer 4 OSI) Internet (Layer 3 OSI) Network Interface (Layer 2,1 OSI)

What does Layer 7 the Application Layer do?

Application Services Service Advertisement

What is the range of well known TCP and UDP ports?

Below 1024

What is the PDU name for the Physical Layer?

Bits

What are the two types of Bandwidth?

Broadband Baseband

What is Circuit switching?

Circuit switching dynamically brings up a dedicated communication link between two parties for those parties to communicate.

Which layer of the OSI Model contains the MAC and LLC sublayers?

Data Link Layer

What is Message Switching?

Data streams are divided into messages, each message is tagged with a destination address and the message travels from one network device to another on their way to the destination.

1. Physical Layer?

Deal with the physical characteristics of the transmission medium, including connectors, pins, use of pins, electrical currents, encoding, light modulation, and the rules for how to activate and deactivate the use of the physical medium.

What is broadband?

Divides the bandwidth available on a medium into different channels

What are some examples of Application Services?

File sharing Email

What are the two functions performed by Connection Services at the Network Layer?

Flow Control Packet reordering

What is Layer 6 Presentation Layer responsible for?

For the formatting of data being exchanged and securing that data with encryption.

What is the PDU name for the Data Link Layer?

Frames

Which OSI layer defines the standards for cabling and connectors?

Layer 1 Physical Layer. The OSI physical layer includes all standards that specify the shape of connectors, wiring in cabling, electrical details, and encoding that the electrical signals use to encode bits over a cable.

What are the Layers of the OSI Model

Layer 1: Physical Layer Layer 2: Data Link Layer Layer 3: Network Layer Layer 4: Transport Layer Layer 5: Session Layer Layer 6: Presentation Layer Layer 7: Application Layer

What layer is Route Discovery and Selection accomplished at?

Layer 3

What Layer of the OSI model is the dividing line between upper and lower layers?

Layer 4 Transport Layer

What are the two sub layers of the Data Link Layer.

MEDIA ACCESS CONTROL (MAC) LOGICAL LINK CONTROL

What does Layer 4 the Transport Layer do?

Messages taken from the upper layers (Layers 5-7) are encapsulated into segments for transmission to lower layers (Layers 1-3)

IP addresses reside at which layer of the OSI model?

Network Layer 3

Is Message Switching suited for real time applications?

No, because of the delay involved.

What type of switching occurs at the Network Layer 3?

Packet Switching Circuit Switching Message Switching

What are the three common switching techniques?

Packet switching Circuit switching Message switching

What is the PDU name for the Network Layer?

Packets

What does the MAC at the Data Link Layer deal with?

Physical Addressing Logical Topology Method of transmitting on the media

What Layer is Synchronizing Bits achieved at?

Physical Layer

What is a common Layer 3 device?

Router

What is another term for Packet Switching?

Routing

What protocol supports a secure connection to a remote host via terminal emulation software?

SSH

What is the PDU name for the Transport Layer?

Segments

Analogy for PDU's and Layers Some People Fear Birthdays

Segments Transport Layer 4 Packets Network Layer 3 Frames Data Link Layer 2 Bits Physical Layer 1

What is Layer 5 the Session Layer responsible for?

Setting up a session Maintaining a session Tearing down a session

What is Service Advertisement? What are some examples?

Some applications send out advertisements making the availability of their services known. Network Printers

At the Layer 4 Transport Layer, what is WINDOWING?

TCP communication uses windowing, in that one or more segments are sent at one time, and a receiver can acknowledge the receipt of all the segments in a window with a single acknowledgment.

Which layer of the OSI Reference Model defines end-to-end delivery of packets?

The Network layer.

What is Asynchronous?

The sender indicates that it is about to start transmitting by sending a start bit to the receiver. When the receiver sees this, it starts its own internal clock to measure the subsequent bits. After the sender transmits its data, it sends a stop bit to indicate that it has finished its transmission.

What is Synchronous?

This approach synchronizes the internal clocks of both the sender and the receiver to ensure that they agree on when bits begin and end

What is Data Formatting at the Layer 6 Presentation Layer responsible for?

This is how text is formatted. The Presentation Layer is responsible for formatting the data in a format that allows compatibility between the communicating devices.

5. Session layer

This layer defines how to start, control, and end conversations (calledsessions). This includes the control and management of multiple bidirectional messages so that the application can be notified if only some of a series of messages are completed. This allows the presentation layer to have a seamless view of an incoming stream of data.

2. Data Link Layer

This layer defines the rules that determine when a device can send data over a particular medium. Data link protocols also define the format of a header and trailer that allows devices attached to the medium to successfully send and receive data.

3. Network Layer

This layer defines three main features: logical addressing, routing (forwarding), and path determination. Routing defines how devices (typically routers) forward packets to their final destination. Logical addressing defines how each device can have an address that can be used by the routing process. Path determination refers to the work done by routing protocols to learn all possible routes and choose the best route.

7. Application layer

This layer provides an interface between the communications software and any applications that need to communicate outside the computer on which the application resides. It also defines processes for user authentication

6. Presentation layer

This layer's main purpose is to define and negotiate data formats, such as ASCII text, EBCDIC text, binary, BCD, and JPEG. Encryption is also defined by OSI as a presentation layer service

What is a example of circuit switching?

Traditional landline call.

Windowing is provided at what layer of the OSI model?

Transport Layer 4

What are the common Protocols in the the Transport Layer?

UDP TCP ICMP